lazy val commonSettings = Seq(
  name := "assembly_demo",
  version := "1.0",
  scalaVersion := "2.13.8",
)

lazy val root = (project in file(".")).
  settings(commonSettings: _*).
  enablePlugins(AssemblyPlugin)

assemblyMergeStrategy in assembly := {
  case PathList("META-INF", xs @ _*) => MergeStrategy.discard
  case x => MergeStrategy.first
}